The friendly skies may be a little too friendly – to infectious disease.

A survey last month in the restrooms of major airports found an alarming number of people don’t wash up after using the facilities – exposing others to the risk of infection.

And guess where the worst offenders were? Kennedy Airport – where more than 30 percent of the travelers flew off without washing up.

At Chicago’s O’Hare Airport, 27 percent did not clean up; and 19 percent failed to wash up in Miami.

By contrast, more than 95 percent of the travelers at Toronto International Airport washed their hands – apparently because Toronto’s recent SARS outbreak has made the locals keenly aware of preventing the spread of disease.

ALL WASHED UP (metro edition)

Here’s how major U.S. airports stacked up when it came to handwashing by air travelers in public rest rooms.